It is a generally accepted view that at least some idioms (phrasemes) occur in the spoken communication primarily. Though this old idea needs a corroboration on extensive data, it is spoken corpora that are being built up in many languages that seem to be an ideal resource for this.
Moreover, the situation of the Czech language appears to be favourable in that there exists a large multi-volume dictionary of idioms which can be used as a reference in background while a series of spoken corpora is now being built, too, some of them being already available.Even a cursory look into a volume of the Czech idiom dictionary (Čermák, 2009 )containing sentence-type idioms offers an interesting part in that many of its very first records start in a "iambic" manner, namely with an unstressed component or word (usually a particle) a. There are some 27 such idioms starting with A and 25 of those containing No standing at the beggining.